Considerable volumes of plastic waste are produced worldwide. Much of the waste plastic ends up in landfills and takes many years to degrade if they ever degrade. Waste plastic is problematic from an environmental point of view and the degradation of the landscape by landfills is undesirable.
Plastic materials are however made of essentially useful compounds that can be used to generate energy.
Processes are known in the art for processing plastic waste materials by thermochemical breakdown of plastic wastes by combustion, gasification or pyrolysis.
Pyrolysis is the preferred method of performing thermochemical break down of waste plastic materials. By varying conditions of a reactor, the composition of the products obtained may be adjusted to meet product needs. A disadvantage of pyrolysis is that the process is traditionally energy intensive owing to the endothermic nature of the physical and chemical processes involved. More specifically, significant energy is required to melt the polymer and to increase the temperature to facilitate the desired chemical reactions. In addition, catalysts may be essential to achieve the desired level of chemical cracking.
It is an object of the present application to address the foregoing problems or to at least to provide the public with a useful choice.
All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinence of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
It is acknowledged that the term ‘comprise’ may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term ‘comprise’ shall have an inclusive meaning—i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term ‘comprised’ or ‘comprising’ is used in relation to one or more steps in a method or process.
Further aspects and advantages of the embodiments described herein will become apparent from the ensuing description that is given by way of example only.